Pontoon boat



FIG. 1 is a perspective view of a pontoon boat showing my new design;

FIG. 2 is a right side elevational view thereof;

FIG. 3 is a left side elevational view thereof;

FIG. 4 is a front elevational view thereof;

FIG. 5 is a rear elevational view thereof; and,

FIG. 6 is a top plan view thereof.

The bottom plan view forms no part of the claimed design. 

The ornamental design for a pontoon boat, as shown and described. 